SAP HCM SEPA process / Country codes conflicts?

I am a technician in PY-IT, so HCM, and I have to enhance the SEPA process for a new Customer in order to instruct the payments of salaries.

I do not know which is the reporting sequence since I have never used them after the new SEPA updates (I mean 2011).

So the first question is: knowing the SEPA xml extractor is SAPFPAYM, is still RPCDTAI0 (for Italy) the first report to be run in order to generate the records on the REGU* tables?

And now the most complicated question: during some implementations and customizations for the Customer, we have been asked to change our Country code on the system. The process is not so easy because many standard reports valid only for the first Country are not available for the new one and the Customer still need to have those reports run periodically.

Knowing that the FI/CO dept has already migrated to the new Country code, and we don't, could any of you gently answer this: is it a problem to link/RFC/run FI/CO and HCM having them two different Country codes?